In one technology, as a vehicle steering device, there is known an electric power steering device (EPS: Electric Power Steering) that applies a steering assistance force to a steering mechanism by activating an electric motor according to a steering force by a driver (a driver) steering a steering wheel (steering wheel). The electric power steering device (EPS) generally includes a torque sensor (torque detection device) that detects the torque generated at a rotation shaft. As a torque sensor in one technology, a technology disclosed in Patent Literature 1 is given, for example. In the torque sensor disclosed in PLT 1, as to a twist amount (torque) of a torsion bar (torsion bar), a rotational displacement with respect to the torque is converted into a physical quantity in roughness and fineness of the magnetic flux by a mountain (protruding part) of the stub, a window of the sleeve of a non-magnetic body, and an excitation coil, and its self-induced electromotive force is measured and converted into a voltage by a circuit. In other words, a torque sensor that detects the voltage to the torque is described. It is to be noted that the torsion bar is a kind of spring using the repulsion force generated when a metal rod is twisted.
In these years, natural and a comfortable steering feeling (feeling of steering) to a driver (driver) is demanded, as a demand for an electronic control unit (ECU: Electronic Control Unit) of the electric power steering device (EPS). For example, high-level control in consideration of the relationship of the road surface repulsion with respect to the steering, convergence, and steering response, and the like is demanded. Even in a method in one technology, it is necessary to control from a low-load region near the beginning (start) of turning the steering wheel to a high-load region near the finishing (end) of the turning, signals of the torque sensor are amplified by hardware or multiplied by software to be used for controlling the electric motor and the like.